TAMPA BAY, Fla. — Mark Luther’s dream home has a window that looks out to a world of water. He can slip out the back door and watch dolphins swim by his private dock. Shore birds squawk from nearby nests in giant mangroves.

He said it’s hard to imagine ever leaving this slice of paradise on St. Petersburg’s Bayou Grande, even though the water he adores is starting to get a little creepy.

Over the 24 years since he moved into the house, the bayou has inched up a protective sea wall and crept toward his front door. As sea level rises, a result of global warming, it contributes to flooding in his Venetian Isles neighborhood and Shore Acres, a neighboring community of homes worth as much as $2.5 million, about 70 times per year.

“Why stay?” asked Luther, an oceanographer who knows perfectly well a hurricane could one day shove 15 feet of water into his living room. “It’s just so nice.”

Tampa Bay is mesmerizing, with 700 miles of shoreline and some of the finest white sand beaches in the nation. But analysts say the metropolitan area is the most vulnerable in the United States to flooding and damage if a major hurricane ever scores a direct hit.

A Boston firm that analyzes potential catastrophic damage reported that the region would lose $175 billion in a storm the size of Hurricane Katrina. A World Bank study called Tampa Bay one of the 10 most at-risk areas on the globe.

Yet the bay area — greater Tampa, St. Petersburg and Clearwater — has barely begun to assess the rate of sea-level rise and address its effects. Its slow response to a major threat is a case study in how American cities reluctantly prepare for the worst, even though signs of impacts from climate change abound all around.

State leaders could be part of the reason. Republican Gov. Rick Scott’s administration has reportedly discouraged employees from using the words “climate change” in official communications. Last month, the Republican-controlled state legislature approved bills allowing any citizen to challenge textbooks and instructional materials, including those that teach the science of evolution and global warming.

The sea in Tampa Bay has risen naturally throughout time, about an inch per decade. But in the early 1990s, scientists say, it accelerated to several inches above normal, so much that recent projections have the bay rising between six inches and more than two feet by the middle of the century and up to nearly seven feet when it ends. On top of that, natural settling is causing land to slowly sink.

Sea-level rise worsens the severity of even small storms, adding to the water that can be pushed ashore. Hard rains now regularly flood neighborhoods in St. Petersburg, Tampa and Clearwater.

(Zoeann Murphy/The Washington Post)

By a stroke of gambler’s luck, Tampa Bay hasn’t suffered a direct hit from a hurricane as powerful as a category 3 or higher in nearly a century. Tampa has doubled down on a bet that another won’t strike anytime soon, investing billions of dollars in high-rise condominiums along the waterfront and shipping port upgrades and expanding a hospital on an island in the middle of the bay to make it one of the largest in the state.

Once-sleepy St. Petersburg has gradually followed suit, adorning its downtown coast with high-rise condominiums, new shops and hotels. The city is in the final stages of a plan to build a $45 million pier as a major attraction that would extend out into the bay.

Worried that area leaders weren’t adequately focused on the downside of living in a tropic, the Tampa Bay Regional Planning Council reminded them of the risks by simulating a worst-case scenario hurricane, a category 5 with winds exceeding 156 mph, to demonstrate what would happen if it entered the Gulf of Mexico and turned their way.

The fictitious Phoenix hurricane scenario projects that wind damage would destroy nearly half a million homes and businesses. About 2 million residents would require medical treatment, and the estimated death toll, more than 2,000, would top the number of people who perished from Hurricane Katrina in Louisiana and Mississippi.

Florida’s most densely populated county, Pinellas, could be sliced in half by a wave of water. The low-lying county of about a million is growing so fast that there’s no land left to develop, and main roads and an interstate connecting it to Tampa get clogged with traffic even on a clear day.

“If a hurricane 4 or 5 hit us,” St. Petersburg City Council Chairman Darden Rice said, referring to the two highest category storms, “there’s no doubt about it. The plan is you’d better get out of Dodge.”

Tampa Mayor Bob Buckhorn’s warning was even starker. Standing outside City Hall last year, he described what would happen if a hurricane as small as a category 3 with 110 mph to 130 mph winds hit downtown.

“Where you’re standing now would be 15 feet under water,” he said.

“You live in a paradise and that’s wonderful, but it has storms.”

Eugene Henry, a mitigation manager for Hillsborough County

Video simulations of hurricanes that strafed Florida but missed Tampa Bay look like an epic game of dodgeball.

“It’s like we’re in this sweet spot. It’s like we’re blessed somehow, protected,” said Allison Yeh, a planner for Hillsborough County in Tampa.

The last direct hit from a category 3 in 1921 left the area in ruins, but few people lived there then. A single death was recorded.

Now, with 4 million residents and gleaming new infrastructure, the stakes are higher, and Yeh and her fellow planners are wary. They know a major hurricane like one of several that barely missed the bay in recent years would have a devastating effect.

There are few hurricane-proof buildings in the bay area. One is a gallery, the Salvador Dali Museum in downtown St. Petersburg with 18-inch-thick concrete walls and pressured glass supported by steel frames that could withstand anything the aforementioned storms could dish out. The building supervisor could stand at the windows and watch a hurricane pass as though it were on the Weather Channel.

(Zoeann Murphy/The Washington Post)

The museum is better protected than one of the largest hospitals in the state, Tampa General, which sits on Davis Island, a spit of earth that was dredged from muck at the bottom of the bay a few years after the last hurricane hit. Buckhorn said a category 3 hurricane would level the island’s houses, including his own.

Tampa General has a thorough evacuation plan, indoor generators that can supply energy for several days, and safe floors with reinforced walls and windows.

But parts of two bridges that lead to and from the island would be cut off by floodwaters, a concern of officials in spite of assurances by the hospital’s managers that there’s a contingency for that, too.

Floridians view hurricanes with the same bravado of Oklahomans who face tornadoes and Californians who brave earthquakes and wildfire: They come with the territory, a fact of life in a tropic, they say.

But other problems are less abstract than big hurricanes. Sea-level rise doesn’t need a megastorm to make its presence felt.

“Even when we don’t take a direct hit, even when it’s a tropical storm or a category 1, the rain it delivers to our city puts enormous stress on our rainwater and sewer collection system,” Rice said.

Water is bubbling up all over Florida. Within the next 12 years, according to an assessment by a group of researchers, Risky Business, the value of state property that will vanish under encroaching water could reach $15 billion. By 2050, it could reach $23 billion.

Along the barrier islands that lured more than 6 million tourists who spent nearly $10 billion last year, governments spend a mix of local and federal funds to renourish beaches lost to erosion that even a tropical storm can cause.

“The bay’s getting higher, and the bay needs to go somewhere else. But there’s nowhere for the water to go,” said Mark Hafen, a University of South Florida instructor who specializes in urban and regional planning.

A team of planners in Hillsborough County said they fight against the potential impact of rising water every day, creating alternative bus routes and detours for flooded roads and trying to get the message out to residents in low-lying areas that their homes could be ruined.

“You live in a paradise, and that’s wonderful, but it has storms,” said Eugene Henry, mitigation manager for Hillsborough County. He preaches about improved coastal inspection, color-coded warnings for residents depending on how low their homes are in a flood zone, making them more aware of the threat so they can take steps to protect themselves.

“If the inevitable monster storm comes, it’s not going to keep you safe from 30 feet of storm surge,” he said, but they’ll know when the tide rises to put shutters up. New structures built on the Florida coast, along with homes seeking major renovations, are mandated to have three feet of clearance from floodwaters.

Storm clouds roll in over downtown Tampa on July 3. (Eve Edelheit/For The Washington Post)

Planners in Tampa Bay are noticing that floodwater is sticking around longer. As the water rises, it’s filling huge outfall pipes, pushing water that would flow down a storm drain back onto streets.

Tampa and Hillsborough County officials have considered levying a tax to help fix a growing problem, but in a state where Republicans opposed to taxes control the governor’s office and the legislature, that’s a tough sell.

“We do have a real challenge with our storm water drainage system,” said Beth Alden, the executive director of Hillsborough Metropolitan Planning Organization, which recently spent millions to clear huge pipes blocked by barnacles left by increasingly swollen tides. “This isn’t a glamorous expenditure, something you’re going to go have a ribbon cutting for.

“It’s something that if we don’t have the funding to keep up, it’s not going to be there. What we’ve been seeing is a very conservative state legislature that has been coming out and trying to reduce the ability of local governments to levy taxes.”

In Hafen’s eyes, there’s an additional problem, one that officials who work at the pleasure of politicians are reluctant to discuss.

“We’ve had a really hard time getting buy-in on sea-level rise on this side of the bay,” Hafen said. “Hillsborough County and Tampa are super conservative. They’re burying their heads in the sand.”

Pinellas County, on the other side of the bay, is more progressive about addressing climate-change impacts, Hafen said. But that didn’t happen until fairly recently. It took a nerdy University of Florida county extension agent to help open everyone’s eyes.

Elizabeth Carnahan was plucked from academia by the county’s director of sustainable living. Her new role was to focus on climate change and engage with others to make the county more resilient to its impacts, and Carnahan took it seriously.

But Carnahan didn’t see a lot of area collaboration in planning.

“They weren’t doing a lot to address climate change and sea-level rise,” she said. “They were willing, but no one was going to the head of the pack to take it on.”

But they were elsewhere, in Gulf Coast states that were hit by Hurricane Katrina and the Southeast Florida area of Fort Lauderdale and Miami that was raked by hurricanes constantly in the first years of the new century.

Amount of high tide inundation under

Category 5 storm surge

1 foot

21 feet or more

Tampa

Int’l

Airport

Tampa

Clearwater

Tampa

General

Hospital

MacDill

AFB

Mariners Cove

Mobile Home

Park

St. Petersburg

5 MILES

Note: Data illustrate height of possible storm surge flooding and are estimates. This map should not be used to replace those used for hurricane evacuation zones. Sources: NOAA SLOSH storm surge data (2014), Florida Geographic Data Library. Population grid data

Carnahan dropped in on their meetings, talked to planners and listened to their sea-level rise projections and vulnerability assessments. After three years of networking outside the bay, she gathered what she considered the best ideas she heard and imported them to Pinellas County.

The county sponsored a three-hour workshop at the Weedon Island Preserve that Mark Luther can see from his flood-risk home. After that gathering, Carnahan noticed a change in officials in the 30 cities in Pinellas County.

“I could see them calling each other a lot more to share what each other were doing,” she said. Watching this, Carnahan’s boss, Mary Campbell, floated an idea to get scientists together to make climate-related recommendations to local governments.

That group became the Climate Science Advisory Panel. Within months, they helped establish the One Bay Resilient Community, looping Hillsborough and Pasco counties into a network that works on climate-related problems.

Tampa Bay now produces a climate report that compares to the National Oceanic and Atmospheric Administration’s National Climate Assessment, offering projections for sea-level rise specifically for their region. It is used to plan bridges and roads, to site government buildings that are supposed to last at least 75 years.

“You hear when it starts to storm and you can’t sleep.”

Jessica Lopez, who lives in a mobile home in an area that frequently floods

Living in near-poverty in Clearwater, Jessica Lopez said she has little time to worry about a threat that might arrive years down the road. For her, the future is now.

Last year around June, she fell asleep as rain pounded her mobile home and awoke to a terrifying sight. The rain hadn’t stopped, and water from an overflowing creek had climbed the stairs to her front door.

Lopez, her husband, Matt, and their daughter, Aurora, were trapped. Water was four feet deep in places, up to her neck. She was six months pregnant with a second daughter.

At least two venomous water moccasins swam past a trailer. A community septic tank that sits directly behind Lopez’s back window flooded. “The feces,” she said, “was everywhere.” She put her head in her hands. “It was so gross.”

The problem got worse. Wet dirt shifted under her trailer, causing it to tilt. Lopez worried they would not survive.

Jessica Lopez lives in the Mariners Cove Mobile Home Park. Last year during Tropical Storm Hermine the water, filled with sewage from a damaged septic tank, came up to her front door. (Zoeann Murphy/The Washington Post)

But Pinellas County rescuers quickly rushed to the scene. The county is so flood prone that the Mariners Cove Mobile Home Park is one of numerous “hot spots” that emergency management department officials watch closely when it storms.

“We know at those locations, if we get too much rain and get high tide, we know they’re vulnerable,” said Kelli Hammer Levy, director of the county’s environmental management division.

Three months later, Mariners Cove Mobile Home Park flooded again when Tropical Storm Hermine took a swipe at Tampa Bay.

Now Lopez is frightened whenever it rains. “You hear when it starts to storm, and you can’t sleep,” she said. “I’m constantly worried now when it floods and the dirt shifts, it’ll tilt us more and more sideways.”

She and her husband had no idea that the mobile park home was a county hot spot when they moved there about a year ago. Like several residents there, she said managers didn’t include that information when they signed leases for the land where their trailers sat.

The county’s floodplain coordinator told Levy that notifying potential tenants of a flood risk is recommended but not required. Renters and leaseholders are often left in the dark.

Leaving is not much of an option, Lopez said. “If we were to move without paying off the trailer, they would undo everything we’ve done. We’ve paid about $2,000. They would just void that.”

Repetitive flooding is so dire that county officials considered buying out the mobile home leasers and relocating them but lacked the funds, Levy said. The county had already spent $300,000 to purchase nearly three dozen homes near McKay and Allen creeks in Largo and relocate the owners.

“People who want to live on the waterfront will always live on the waterfront.”

Mark Luther, an oceanographer who lives on the water in the Venetian Isle neighborhood

In Shore Acres, the wealthy community next to Mark Luther’s neighborhood, residents are much better informed about the area’s flooding, and have far more options.

Like Lopez, they’re staying. Many Venetian Isles and Shore Acres residents have poured thousands of dollars into homes to accent their bayou views.

But it might be a trap.

Nearly all of Shore Acres is considered a repetitive loss area where homes have flooded more than once and required compensation from insurers. Street flooding happens after rains and high tides.

Eighty percent of homes in the area are what planners call “slab-on-grade.” It means their living rooms are one step from the ground or less. More than 1,500 are subject to flooding, according to an analysis of repetitive loss flooding by the city of St. Petersburg.

Since 1978, 29 homes have made 129 flood insurance claims totaling $2.9 million. A significant flood or a catastrophic storm could ruin a thousand more, triggering major insurance claims.

Mark Luther, a professor of marine science who studies climate change, lives near the water. He says if a major hurricane were to hit his home would likely be destroyed. (Zoeann Murphy/The Washington Post)

St. Petersburg, like Tampa, is spending millions in an attempt to clear storm drains that are supposed to collect water from streets and dump it back into Tampa Bay. The city is also imploring owners of slab-on-grade homes to consider building mounds to raise them three feet from the ground.

It’s a tough sell for someone like Luther, whose home was built long before anyone started talking about accelerated sea-level rise.

“I’m not sure you can elevate this type of house,” he said. “It’s U-shaped and fairly large, 3,700 square feet.” Luther’s house is brick with terrazzo floors “that would crack to pieces.”

But there’s one option that Venetian Isles residents have that Lopez in her Clearwater trailer park does not, and Luther is considering it. The real estate market in paradise is hot, and he can sell.

“People who want to live on the waterfront will always live on the waterfront,” Luther said, a reference to the rich. “Every house on my street that sold within the past 10 years, they’ve knocked it down and built a 10,000- or 12,000-square-foot mini-mansion on top of it.”

Carnahan seconded that. On the edge of Tampa Bay, where the danger from a colossal storm is worse, homes in Venetian Isles and flood-prone Shore Acres are still being snatched up.